Council is currently trialing sonic nets to make two sites in the centre of Dubbo inhospitable.

Last year council turned to birds of prey to deter the birds, but council’s manager landcare services Lynton Auld said it was an extremely difficult program to coordinate.

“Falcons appear to be effective when their presence coincides with a change of weather but it is difficult to program as they are in high demand from other centres with similar problems,” Mr Auld said.

“Falcons were utilised in 2014 and 2016 with good results. However they were unavailable in 2015 and available too late in the season for 2017. As a result we have investigated the use of a sonic net.”

The product has been developed in the USA. It aims to make the environment of the target species, which can be any bird or animal, unhospitable, so they will choose to go elsewhere, Mr Auld said.

The net works by projected a specific sound file over a target area, in this case the preferred roost trees in Macquarie Street.

A trial has taken place outside the Subway at Riverdale and Sportspower where the starlings are known to roost.

The projected sound can currently be heard on the street as a low level white noise, similar to static from a TV, except for a short targeted period of high volume each night.

Mr Auld said the higher volume was designed to coincide with peak starling arrival and was no louder than the starlings themselves.

“From observing the first nights’ installation it’s possible we may have found a solution to the starlings in the starlings in the CBD. Large numbers of birds were relocated using the technology and did not recolonise the target trees,” the manager landcare services said.

Council would continue to trial the system and monitor the behaviour of the birds before a decision was made on whether to implement the sonic net on a broader scale within the CBD, he said.

Starlings in the CBD are a concern due to the public health risks, as well as the retail and council clean-up costs.

In the past council has tried nets, water cannons, laser lights and fake distress calls to encourage the birds to roost elsewhere.